Mechanism for operating counters for draw benches



Sept. s, 1953 J. B. HIGGS 2,651,465 MECHANISM FOR OPERATING COUNTERS FORDRAW BENCHES Filed July 2, 1951 m 1 2O 7 a G O G O o 8 6 o o 9 2a {6 8 18 14 a Z 14 I5 0 O (5 'T\ 7 Patented Sept. 8, 1953 MECHANISM FOR OPERATING COUNTERS FOR DRAW BENCHES John B. Higgs, Prospect, South Australia, Australia, assignor to British Tube Mills (Australia) Proprietary Limited, Kilburn, South Australia,

Australia Application July 2, 1951, Serial No. 234,816 In Australia July 6, 1950 3 Claims.

This invention relates to an improved mechanism for operating a counter for multiple die draw benches.

During the operation of draw benches it is desirable to count the number of tubes or work pieces drawn and also to record the footage of such tubes or work pieces, this having been previously achieved by placing a switch adjacent the die plates of the bench and actuating this switch through movement of the die plate when drawing is actually taking place, the switch then controlling the counter itself which consists of a measuring member in contact with a driven part of the bench which is moved by electrical control from the switch so that while a work piece is being drawn unit length is measured by the counter, the electrical circuit also being so arranged that when a draw first commences a second counter is initiated to record the tube. In this specification the said counter will not be referred to as details ofv same are already contained in my earlier patent application Serial No. 706,370 dated October 29, 1946, now Patent No. 2,561,512.

While this indicator was satisfactory for smaller draw benches and particularly those having only a single die it was open to certain difficulties when applied to larger draw benches of the multi-die type, one of these difficulties being the inability to conveniently mount both dies in movable members whereby the switches can be actuated and also maintaining of the circuit should chatter of the die occur. It will be appreciated that when drawing tubes or the like through a die the forces set up in the die are extremely heavy and under some conditions die chatter, which is in an axial direction in relation to the piece'being drawn, may aifect the counting unless a considerable movement of the die was permitted in the initial switching action but such excessive die movement is not generally desirable.

According to my invention two separate switch means are included in each counting circuit, the "first switch means being associated with the grips which engage each of the work pieces and the other with a stressed part of the draw .bench which will actuate the switch means associated with it only when actual draw is taking place, the switch means for each counting circuit being connected in series.

In this way should a grip fail or should one work piece be shorter than another, which often is the case, the switch means connected with that grip will be moved to stop energization of that counter circuit, while the other switch means in that circuit will be set to commence counting only when actual draw takes place and not as soon as the grips engage a work piece.

In order, however, that the invention may be more clearly understood it will now be described with reference to the accompanying drawings in which:

Fig. 1 is a side elevation of a carriage of a tube draw bench removed from its tracks to indicate in the general the position it occupies during a draw,

Fig. 2 is a front elevation of Fig. 1 showing the carriage and chain tracks in section, and

Fig. 3 shows the electrical circuit diagram.

The carriage l is provided with the normal front wheels 2 and rear Wheels 3 operating on the tracks of the draw bench counter supporting frames 4, these frames having in them channels 5 in which two draw chains 6 operate.

Mounted on each side of the carriage I are the chain grips T the hooks 8 of which are adapted to engage the links of the chains 6, these grips i being pivoted to the draw bench in extensions 9 so that they can move downwards to pick up the chains 6 but when the actual draw is taking place can move up to the position shown in Fig. 1 in which the tension portion of the chain 6 is lifted clear of the bottoms of the channels 5 in which such chains normally operate.

.I'he grips in which the tubes are engaged and which can be of any known construction are not shown in the drawings as they form no material part of this invention, but the levers II] which move with the grips are shown, as movement of these is utilised in this invention.

Mounted near the front of the draw bench on brackets M are switches 15 the movable stems it of which project downwardly into the path of the chains 5, these switches i5 being so arranged that when the draw bench is inoperative and the chains 6 lie along the bottoms of the channels 5 the switches are open but as soon as the draw commences and the chains are lifted due to the resistance of the draw the stems iii are contacted by the chain and the switches l5 are closed.

This motion alone could be used to operate the tube counting and measuring apparatus, and in a single-die bench would be quite satisfactory but in a multiple-die bench the moving on the draw chains 6 will take place even if only one of the tubes is being drawn such as where one of the tube grips does not engage the tube tag or slips off when the draw commences, and to ensure that a correct record is made of the tubes and tube lengths two further switches it are used, the stems IQ of these projecting into the path of the grip levers ii! so that when the grips are closed on to the tag end of a tube the switches is also will be closed.

By then placing the switches and It on each side of the draw bench in series as shown in Fig. 3 of the drawings, counting will be efiected independently for each of the tubes, the slipping of one of the grips or breaking of one tube immediately causing disengagement of the grip and re-positioning of same in its open position with consequent movement of the associated lever it to break the circuit on that side of the bench.

It will also be appreciated that under some conditions it would. be possible to utilise switches I 8 only but it is generally preferable to utilise the switches I5 and I8 in series.

The switches l8 instead of being associated with the levers I!) could be otherwise located, for instance as adjacent the weights which open the jaws when the drawing force on same has been removed.

As the carriage 8 moves along the tracks of the main frames d during the drawing operation brushes 22 are supported from a bracket 23 extending from the side of the carriage, these brushes engaging collector rails 24 in a channel 25 supported on the track frames 4 of the bench.

The collector rails 24 are in turn each electrically coupled to the solenoids 2? of the switches 28 which in turn are in circuit with the actuating solenoids 29 of the counter itself, it being preferred to utilise a low voltage for the operation of the switches 28 as the collector rails 24 must extend along the full length of the track frame 4 of the bench, the low voltage preferably being supplied from a transformer 30.

While a low voltage supply has been shown for the collector rails 24 this is not essential and the collector rails could if desired be connected directly to the solenoids or other actuating means of the counter itself.

In operation when the carriage is moved to the starting end of the bench and the grips on the carriage engage and lock on to the tag ends of the tubes the switches it are closed but until the actual draw takes place the circuit itself remains open as the draw chains do not rise until full tension is applied to these. As soon, however, as the hooks 8 are dropped to engage the chains the tensioned portion of the chains will swing up to a position approximating that where the line of pull passes through the pivot of the members 1, this action causing the chains 6 to contact the stems is of the switches 55 and closing these whereupon the circuit to the counter is com- .4 pleted as the draw continues will remain completed until such time as the end of the first drawn tube clears the die whereupon the lever [0 associated with that grip will be returned and that circuit broken, the other circuit being broken when the remaining tube is completely drawn and leaves the die whereupon the lever It associated with it will be returned and also as the tension is now removed from the carriage the chains 5 will drop from the hooks 8 so that both the switches l5 and 18 are now broken.

Because the switches on the grips must close when the grips engage the tag ends of the tubes, but as at that stage the draw has not commenced, it is necessary to use the chain actuated switches to cause measuring to be initiated at the correct time. The use of the chain actuated switch or switches only would not give a reliable check as should one of the grips on a multiple draw bench release or slip the remaining tube or tubes would still cause the draw to be recorded by deilection of the draw chains.

What I claim is:

' 1. Improved mechanism for operating a counter for multiple draw benches having a draw carriage movable on tracks by draw members engaged by movable hook members which lift and stress the draw members during the draw due to the mounting of the hook members, and in which grips on said draw carriage engaged on the tag ends of work pieces projecting through die plates and draw said work pieces through the dies as the carriage moves forward, comp-rising independent switch means associated with each of said grips and positioned to be actuated by movement of said grip when it engages or releases the work pieces, and switch means supported from the carriage in the path of a draw member when lifted and stressed by the resistance of the draw when the carriage is drawn forward, the first said switch means for each said grip being in series with the second said switch means so that the counter mechanism is energised only while said switch means associated with the grip and said switch means associated with the draw member are similarly set.

2. Improved mechanism for operating a counter for multiple draw benches having a draw carriage movable on tracks by chains engaged by movable hook members which lift the chains during the draw due to the mounting of the hook member, and in which grips on said draw carriage engaged on the tag ends of work pieces projecting through die plates and draws said work pieces through the dies as the carriage moves forward, comprising independent switch means associated with each of said grips and each positioned to be actuated by movement of its said grip when it engages or releases the work pieces, and switch means supported from the carriage in the path of a draw chain which is displaced by the resistance of the draw when the carriage is drawn forward, the first said switch means for each said grip being in series with the second switch means so that the counter mechanism is energised only while said switch means associated with the grip and said switch means associated with the draw chain are similarly set.

3. Improved mechanism for operating a counter for multiple draw benches having a draw carriage movable on tracks by chains engaged by movable hook members which lift the chains during the draw due to the mounting of the hook members, and in which grips on said draw carriage engaged on the tag ends of work pieces projecting through die plates and draw said work pieces through the dies as the carriage moves forward, comprising levers on said grips, independent switch means in the path of each of said levers arranged to be closed by movement 6 of said lever when the grip engages the Work piece, and switch means supported from the carriage in the path of a chain to be closed when the chain is lifted due to the resistance of the draw when the carriage moves forward, the first said switch means for each said grip being in series with the second said switch means so that the counter mechanism is energised only while said switch means associated with the grip and said switch means associated with the chain are both closed.

JOHN B. HIGGS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,208,270 Grout July 16, 1940 2,544,895 Nelson Mar. 13, 1951 FOREIGN PATENTS Number Country Date 429,025 Germany May 17, 1926 

